A deuteron particle (the nucleus of an isotope of hydrogen consisting of one proton and one neutron and having a mass of 3.34×10?27 kg) moving horizontally enters a uniform, vertical, 0.700T magnetic field and follows a circular arc of radius 55.5cm .
A) How fast was this deuteron moving just before it entered the magnetic field ?
B) How fast was this deuteron moving just after it came out of the field?
C) What would be the radius of the arc followed by a proton that entered the field with the same velocity as the deuteron?